Late in the day (EST) on August 22, Microsoft officials noted that the infrastructure required for developers to submit Windows Phone "Mango" applications to the Marketplace was beginning to come online.

"The infrastructure for accepting your Mango apps is coming online as we speak! Some of you may already be seeing new content as we conduct a final round of tests. Stay tuned for a more detailed overview of the Mango app submission process within the next 24 hours," read a post on the blog.

Brandon Watson, the Director for Developer Experience on the Windows Phone team, has been reaching out to potentially disenfranchised webOS developers in an attempt to get them to target the Windows Phone Mango platform. Watson said earlier today that he had received close to 1,000 emails in response to his webOS pitch.

Microsoft announced it had released to manufacturing the Windows Phone Mango (Windows Phone OS 7.1) bits in late July. Microsoft provided those bits to handset makers and carriers for testing. Once they give Microsoft the OK, the company can begin scheduling Mango to be pushed to existing Windows Phone handset owners. Microsoft officials also have said that new phones running Mango will be available this fall.

Update (August 23): At TechEd in Auckland, Microsoft and partners Asus and Acer showed off two new Mango phones, reports Windows Phone NZ's Paul Spain. The Asus phone seems to be an engineering prototype which could possibly have a front-facing camera; the Acer model is the M310.

Update No. 2 (August 23): The Zune 4.8 client software, which supports Mango phones, is available for download, as well.